1. Field
Exemplary embodiments of the present invention relate to a voltage generation circuit which generates a high-level voltage through boosting of an input voltage.
2. Description of the Related Art
A semiconductor device includes internal circuits operating with voltages that are supplied from an external power source. However, since operating voltages having various levels are used in the semiconductor device, it is difficult for the external power source to supply all the operating voltages that are used in the internal circuits of the semiconductor device. Accordingly, a semiconductor device includes voltage generation circuits to internally generate operating voltages having different levels.
Particularly, in a device that uses a battery as an external power source, if a level of a power supply voltage supplied from the battery is lower than levels of voltages required to operate internal circuits in the device, it is necessary to internally generate the required voltages whose levels are higher than the power supply voltage supplied from the battery. In order to generate a high-level voltage that is higher than the power supply voltage from the external power source, a charge pump circuit may be used. A method for generating a high-level voltage using the charge pump circuit may include (1) a single-regulation method which directly generates a target voltage through the charge pumping, and (2) a double-regulation method which generates a higher voltage than a target voltage through the charge pumping and then generates the target voltage through regulation of the higher voltage. The single-regulation method may reduce current consumption in generating the target voltage, but may generate voltage ripples in the target voltage. On the other hand, while the double-regulation method may generate a stabilized target voltage, it may increase the current consumption in generating the target voltage.
Accordingly, in generating a higher voltage than an external power supply voltage, there is a need for developing a method that can stabilize a level of the higher voltage and reduce the current consumption, compared to the single-regulation method and the double-regulation method.